Known in the art is an internal combustion engine which is comprised of a particulate filter which is arranged inside of an engine exhaust passage, a fuel addition valve which is arranged in the engine exhaust passage upstream of the particulate filter, and a temperature sensor for detecting a temperature of the particulate filter and which, when the particulate filter should be regenerated, injects fuel from the fuel addition valve and uses the heat of oxidation reaction of the injected fuel to make the temperature of the particulate filter rise to a 600° C. or so regeneration temperature. In this regard, if the fuel addition valve is clogged, even if the fuel addition valve injects fuel, the temperature of the particulate filter will no longer rise to the regeneration temperature. Therefore, in this internal combustion engine, when the temperature of the particulate filter does not rise to the regeneration temperature even if injecting fuel from the fuel addition valve, it is judged that the fuel addition valve is clogged (for example, see PTL 1).